Harrison+17 (KMOS, $z=1$)

Spiral galaxies $\leftrightarrow$ high $J_\star$: also at high-$z$

$M_\star, J_\star,M_\mathrm{BH}$, morpho, bulge fraction, …

What causes what?

Cosmology & angular momentum

Correlation between environment & galaxy properties (cf previous session!)

Weak lensing signal

Classical model of gal form

1

2

 3 

$M_\mathrm{DM}, j_\mathrm{DM}, \dots$

4

$M_\star, j_\star, \dots$

Hierarchical clustering

$N$-body physics

Accretion of gas
star form, feedback, cooling, ...

Classical model of gal form

1

2

$M_\mathrm{DM}, j_\mathrm{DM}, \dots$

4

$M_\star, j_\star, \dots$

Hierarchical clustering

$N$-body physics

Accretion of gas
star form, feedback, cooling, ...

Part I

 3 

Classical model of gal form

1

2

$M_\mathrm{DM}$,
$j_\mathrm{DM}, \dots$

4

$M_\star$,
$j_\star, \dots$

Hierarchical clustering

$N$-body physics

Accretion of gas
star form, feedback, cooling, ...

Part I

Part II

 3 

$z=0$

$z = 100$

$$\mathbf{L}_\mathrm{lin.} \propto \int\mathrm{d}^3q(\mathbf{q}-\bar{\mathbf{q}})\times \nabla\phi$$

[White 84]

$z=0$

$z = 100$

[Porciani+02]

$z=0$

$z = 100$

[Genetic modifications: Roth+16, see also Rey&Pontzen 18, Stopyra+20]

Predicting angular momentum

Predicting angular momentum

• Angular momentum of individual regions can be predicted accurately.
• AM of halos ⇒ requires boundaries of patch

[On patch boundaries: see Lucie-Smith+18]

Can we control baryonic
angular momentum?

Wechsler & Tinker 18

${\color{red}M_\star} / M_\mathrm{h} \ll \Omega_b / \Omega_m$
⇒ baryons & DM stem from different regions

[On ≠ patch: see Liao+17]

$l_0 \times 0.66$

$l_0 \times 0.8$

$l_0 \times 1.2$

$l_0 \times 1.5$

$l_0 \times 0.66$

$l_0 \times 0.8$

$l_0 \times 1.2$

$l_0 \times 1.5$

What drives AM up/down?

Conclusion & outlook

• angular momentum of DM is predictable
   

• boundary of halos in the ICs is a hard problem
  ⇒ limits practicality of predictions
   

• stellar AM can be controlled!
  ⇒ imposed by mergers
  ⇒ controls B/T, $v/\sigma$, morpho, …
  ⇒ weak lensing predictions easier than expected?
   

$l_0 \times 1.2$

$l_0 \times 1.5$

$l_0 \times 0.66$

$l_0 \times 0.8$